update scaleio.py with resize function
update scaleio.py with resize function

adding resize_volume(), which needs a size in GB, and the GB new size must be larger than the existing size, ScaleIO will automatically round up, or we can eventually make sure it round up in this function to nearest 8GB allocation granularity.
swevm/scaleio-py,samwyse/scaleio-py,wallnerryan/scaleio-py